Ion-Based Cellular Signal Transmission, Principles of Minimum Information Loss, and Evolution by Natural Selection
Ion-Based Cellular Signal Transmission, Principles of Minimum Information Loss, and Evolution by Natural Selection
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DOI：
10.3390/ijms21010009
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发表时间：
2020-01-01
影响因子：
5.6
通讯作者：
Gatenby, Robert
中科院分区：
文献类型：
--
作者：
Frieden, B. Roy;Gatenby, Robert
极端物理信息EPI原则指出，最大的信息传输，或等效地，最小的信息损失是自然的基本属性。先前的工作已经证明了通用EPI原理允许导出几乎所有的物理定律。在这里，我们调查EPI是否可以类似地产生生命的基本法则：进化。生命系统需要信息来生存和增殖。基因组中的遗传信息编码细胞大分子的结构和功能，但这些信息随着时间的推移而保持固定。相反，细胞必须快速和持续地访问，分析和响应环境中不断变化的空间和时间信息。我们认为这两种信息动力学是相互联系的，因为基因编码大分子的结构，这些大分子形成与外部环境动态相互作用所必需的信息管道。然而，由于基因组没有能力精确定位外部信号的时间和位置，我们认为细胞膜是接收和处理大多数外部信息的场所。在我们的模型中，一个外部信号被跨膜离子通道上的门检测到，并通过离子传输到细胞质中，当门打开时，离子沿着沿着预先存在的浓度梯度流动。由此产生的细胞质离子“喷流”在时间和空间上都是局部的，从而产生空间和时间信息。细胞质中的小的局部信号通过外周膜蛋白的功能和位置的改变而被“处理”。较大的扰动产生细胞质离子浓度的长期或空间上广泛的变化，这些变化可以通过离子流沿着细胞骨架的元素传递到其他细胞器。对不断增加的环境信息获取的一个进化限制是这样做的成本。这种权衡的一个解决方案是信息管道的发展，使传输过程中的信号损失最小化。由于这些管道的结构在基因组中编码，因此使信号损失最小化的大分子管道的进化与称为极端物理信息（EPI）的普遍原则有关，并且实际上受其支配。基于离子通过膜通道和沿着线状细胞骨架大分子流动的信息动力学的数学分析满足EPI原理。因此，自然选择进化的经验模型，虽然只适用于生命系统，但在理论上是基于一个普遍的原则，也可以用来推导物理定律。最后，如果信号损失最小化是克服能量约束的机制，则该模型预测增加的信息和相关的复杂性与能量产生的效率提高或底物采集的改善密切相关。
The Extreme Physical Information EPI principle states that maximum information transmission or, equivalently, a minimum information loss is a fundamental property of nature. Prior work has demonstrated the universal EPI principle allows derivation of nearly all physical laws. Here, we investigate whether EPI can similarly give rise to the fundamental law of life: Evolution. Living systems require information to survive and proliferate. Heritable information in the genome encodes the structure and function of cellular macromolecules but this information remains fixed over time. In contrast, a cell must rapidly and continuously access, analyze, and respond to a wide range of continuously changing spatial and temporal information in the environment. We propose these two information dynamics are linked because the genes encode the structure of the macromolecules that form information conduits necessary for the dynamical interactions with the external environment. However, because the genome does not have the capacity to precisely locate the time and location of external signals, we propose the cell membrane is the site at which most external information is received and processed. In our model, an external signal is detected by gates on transmembrane ion channel and transmitted into the cytoplasm through ions that flow along pre-existing concentration gradients when the gate opens. The resulting cytoplasmic ion "puff" is localized in both time and space, thus producing spatial and temporal information. Small, localized signals in the cytoplasm are "processed" through alterations in the function and location of peripheral membrane proteins. Larger perturbations produce prolonged or spatially extensive changes in cytoplasmic ion concentrations that can be transmitted to other organelles via ion flows along elements of the cytoskeleton. An evolutionary constraint to the ever-increasing acquisition of environmental information is the cost of doing so. One solution to this trade-off is the evolution of information conduits that minimize signal loss during transmission. Since the structures of these conduits are encoded in the genome, evolution of macromolecular conduits that minimize signal loss is linked to and, in fact, governed by a universal principle, termed extreme physical information (EPI). Mathematical analysis of information dynamics based on the flow of ions through membrane channels and along wire-like cytoskeleton macromolecules fulfills the EPI principle. Thus, the empirically derived model of evolution by natural selection, although uniquely applicable to living systems, is theoretically grounded in a universal principle that can also be used to derive the laws of physics. Finally, if minimization of signal loss is a mechanism to overcome energy constraints, the model predicts increasing information and associated complexity are closely linked to increased efficiency of energy production or improved substrate acquisition.